The HTML5 Video Player – mp4 Video Player Plugin and Block plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on multiple functions called via the 'h5vp_ajax_handler' ajax action in all versions up to, and including, 2.5.32. This makes it possible for unauthenticated attackers to call these functions to manipulate data.
https://plugins.trac.wordpress.org/changeset/3139559/
https://plugins.trac.wordpress.org/browser/html5-video-player/trunk/inc/Model/ImportData.php#L4
https://plugins.trac.wordpress.org/browser/html5-video-player/trunk/inc/Model/Ajax.php#L5